1. Field of the Invention
The present invention relates to an electrophotographic electrically conductive member used for electrophotographic apparatuses and process cartridges.
2. Description of the Related Art
In image forming apparatuses using an electrophotographic method, namely, electrophotographic apparatuses, electrically conductive members are used in various applications, i.e., as members such as a charging member, a developing member, and a transfer member. In the electrophotographic apparatus, a charging roller as a charging member is disposed in contact with an electrophotographic photosensitive member to charge the electrophotographic photosensitive member. The charging roller comprises an electrically conductive layer. In order to control conductivity of the electrically conductive layer, an electron conductive agent such as carbon black, or an ion conductive agent such as quaternary ammonium salt compounds is added to the electrically conductive layer. The ion conductive agent is more uniformly dispersed in a binder resin than the electron conductive agent. In Japanese Patent Application Laid-Open No. H01-142569, an ion conductive agent is selected as the conductive agent in order to reduce unevenness of electric resistance attributed to the conductive agent unevenly dispersed in a binder resin.
Japanese Patent Application Laid-Open No. 2003-202722 uses a hydrophobic ion liquid as an ion conductive agent to improve the increase in electric resistance under a low temperature and a low humidity.